Each rifle has different harmonics when fired so the barrels are adjusted to suit the given load. Now that you have mentioned that it is a quality brand and as NitroX said, contact Beretta in Melbourne http://www.berettaaustralia.com.au/beretta/ who if they don't know can find out from the factory, the other alternative is go direct to the factory for information. http://www.beretta.com/

Cheers,

Jeff Gray

.